Further developments
Initially second to the 747 as Boeing's most profitable jetliner,[92] the 777 has since become the company's most lucrative model.[93] In 2000, program sales accounted for an estimated US$400 million of Boeing's pretax earnings, US$50 million more than the 747.[92] By 2004, the airliner comprised the bulk of wide-body revenues for the Boeing Commercial Airplanes division.[94]In 2007, orders for second-generation 777 models approached 350 aircraft,[95] and in November of that year, Boeing announced that all production slots were sold out to 2012.[81] The program backlog of 356 orders was valued at US$95 billion at list prices in 2008.[96] In 2010, Boeing revealed plans to increase 777 production from 5 aircraft per month to 7 aircraft per month by mid-2011, and 8.3 per month by early 2013.[97] Complete assembly of each 777-300ER requires 49 days.[98]
In the late 2000s, the 777 faced the possibility of increased competition from Airbus' planned A350 XWB and internally from proposed variants of the 787,[95] both airliners that promise fuel efficiency improvements. As a consequence, the 777-300ER received an engine and aerodynamics improvement package for reduced drag and weight.[99] In 2010, the variant further received a 5,000 lb (2,300 kg) maximum zero-fuel weight increase, equivalent to a higher payload of 20–25 passengers; its GE90-115B1 engines received a 1–2.5 percent thrust enhancement for increased takeoff weights at higher-altitude airports.[99] More design changes were targeted for late 2012, including possible extension of the wingspan,[99] along with other major changes, including a composite wing, new powerplant, and different fuselage lengths.[99][100][101] Emirates has been reported as working closely with Boeing on the project, and may be the aircraft's launch customer.[102]
In September 2011, Boeing and General Electric released more details on new 777 versions, tentatively designated 777-8X and 777-9X.[103] Wingspan is expected to increase from the current 212 ft 7 in (64.8 m) to 234 feet (71.3 m).[87][103] In addition, gross weight is tentatively slated to decrease slightly from the current 775,000 lb (352,000 kg) to approximately 759,000 lb (344,000 kg) for the −9X model.[104] General Electric has announced studies on a slightly smaller engine, dubbed the GE9X, to power the proposed variant. It will feature the same fan diameter from the GE90-115B (128 in (325 cm)) and a thrust decrease to new ratings of 99,500 lbf (443 kN) per engine for the –9X and –8XL, and 88,000 lbf (390 kN) for the –8X.[105][106][107] Rolls-Royce and Pratt & Whitney have also proposed powerplants for new 777 models, including the RB3025 concept, based off the Trent 1000 and Trent XWB engines, and an adaptation of PW1000G engine architecture to produce up to 100,000 lbf (440 kN) of thrust.[103] Boeing is also studying an ultra long-range replacement for the 777-200LR, conceptually dubbed the 777-8LX, which would share the –9X's fuel capacity and gross weight. Its range is to be 9,480 nmi (17,560 km) compared to 9,395 nmi (17,400 km) for the -200LR.[104] The 777-8LX's fuselage length would match that of the proposed −8X at 228.17 feet (69.5 m).[103] The 777-9X would feature a fuselage stretch of 7.0 feet (2.13 m) and extended horizontal stabilizers from the −300ER to a total length of 250 feet 11 inches (76.5 m) to accommodate 407 passengers.[104][108] Preliminary estimates place entry into service around 2019.[109][110] In 2012, Boeing has slowed 777X development, but still plans for it to begin service by about 2019.[111]
In November 2011, Boeing began assembly of the 1,000th 777, a −300ER model for Emirates;[98] the aircraft was rolled out in March 2012.[112] In late 2011, the FAA assigned a common type rating to the 787 and 777, allowing pilots qualified on either aircraft to operate both models, due to related design features.[113] According to industry reports, the aircraft may eventually be replaced by a new product family, the Boeing Yellowstone 3, which would draw upon technologies from the 787.[95]
0 komentar:
Posting Komentar